Correction to readme on licensing

[Ruben Rodriguez]

Hi, could we please change the last line in the readme, currently reading:

"This project is available as open source under the terms of the GPL 3.0
or later. However, some elements are being licensed under MIT license
and MPL 2.0 license. For accurate information, please check individual
files. As well as for accurate information regarding copyrights."

Since the project is overall licensed under GPL, it is not necessary to
indicate that some components are licensed under a compatible license.
It currently sounds as if there was something unusual about the license.
Also, at the FSF we use the term "Free Software". :)

I suggest this simpler version:

"This project is available as free software under the terms of the GNU
General Public License 3.0 or any later version."